1. Field of the Invention
This invention relates to the field of mobile device power sources, and particularly to manually operated power sources for such devices.
2. Description of the Related Art
Mobile electrical and electronic devices such as cell phones, radios and flashlights, are typically powered by batteries, which may become discharged at inopportune times. Several approaches have been employed to overcome this problem. For example, some mobile devices are provided with a small integral generator which is operated with a crank or by being shaken. Prior to using the device, a user operates the crank or shakes the device; the resulting power charges a battery or other energy storage device, thereby allowing the device to be used for period of time. However, since power generation requires that the device be cranked or shaken, it is difficult or impossible to operate the device while generating the power, thereby necessitating that the power be generated prior to the device being used.
In addition to not being able to power and use the device simultaneously, this approach has additional drawbacks. More time and energy may be expended generating power than is necessary to ensure that the device does not run out while being used. Furthermore, the time delay inherent in this sequential approach may be annoying, and in some cases, involving emergency situations, dangerous.